Draft means for locomotives



April 1, 1941. A. M. BE VIER DRAFT MEANS FOR LOCOMOTIVES Filed April 4, 1940 INVENTOR. BY W w.

ATT'ORNEY.

Patented Apr. 1, 1941 UNITED STATES PATENT OFFICE.

DRAFT MEANS F OR LOCOMOTIVES Abram M. Bevier, Duluth, Minn.

Application April 4, 1940, Serial No. 327,793

1 Claim.

This invention relates to draft mechanism for locomotive boilers and the principal object of which is to provide a more efficient and simple form of discharge nozzle from the engine into the smoke box of the boiler.

Another object of the invention is to so design the exhaust discharge nozzle of the engine in a manner that there will be a minimum of back pressure of steam on the piston head, and still provide adequate means for varying the efiect of the exhaust on the draft of the fire box.

Other objects and advantages of the invention will appear in the following description thereof.

Referring now to the accompanying drawing, forming part of this application, and wherein like reference characters indicate like parts:

Fig. 1 represents a transverse section through the smoke box of the boiler and improved nozzle as associated therewith.

Fig. 2 is a top plan view of the nozzle.

Fig. 3 is a central vertical section of the nozzle showing the division wall and plug in elevation.

l represents the front end of the boiler of a locomotive and 2 the smoke box chamber, while 3 and 4 represent the exhaust ports or ducts leading from the engine cylinder upon either side and below the boiler, and which is representative of the common arrangement of such parts.

In such arrangement the terminals of the two ports 3 and 4 are usually brought closely together when they enter the smoke box of the boiler and in this instance they are illustrated as discharging directly into the upstanding cylindrical nozzle 5, the lower end of which communicates only with such terminals, that is to say there is preferably no connection at this end of the nozzle with the interior of the smoke box. The nozzle 5 is divided into two equal parts as indicated by the central vertical wall 6 which is disposed directly beneath and aligned with the axis of the boiler so that each exhaust terminal is directly below its respective single chambered half of the nozzle. However, the division wall 6 does not extend the entire height of the nozzle 5 but rather terminates considerably short of same,

leaving a cylindrical space or chamber indicated at IU thereabove with the exception that, fixed centrally upon the upper edge of said division wall is a combined cylindrical and conically shaped enlargement or hub-like portion I having a central internally screw-threaded bore for the reception of the screw threaded shank 8 of the removable plug 9, the upper end of which terminates preferably in the same plane with the upper end of the nozzle 5. This construction of center plug in relation to the upper end of the nozzle is to insure as nearly as possible a pistonlike exhaust of the discharge from each of the exhausts as they alternately take place, this being evidenced frequently by the large number of ring like volumes of smoke emitted from the stack of the locomotive whensuch an apparatus is employed therein.

Furthermore, the control of this piston like action under different circumstances is readily accomplished by the substitution of one size of plug 9 for another, and which relationship of plug to the size of nozzle and work being accomplished controls the effect of the exhaust on the fire in the boiler. By this construction, it will be noted that the conduit or passageway for the exhaust of each cylinder of the engine is in no way restricted or effected until the same reaches the upper edge of the division wall 6, being substantially constant in its cross sectional area throughout, but, at this point, relief is provided for the exhaust in that it may expand to the full capacity of the nozzle 5 and by so doing the pressure within said enlarged portion of the nozzle is materially reduced at each exhaust, thus providing an opportunity for regulating the speed of discharge from the nozzle into the lower flared end of the stack, indicated at H, or the flared end of a petticoat, if same is employed. Thus it is seen that plugs, one of which is indicated at 9, of different diameters, may be employed without producing any back pressure upon the piston of the engine, provided, of course, that the plug used is not of a size to increase the pressure within the chamber l0 materially above that at the termination of each exhaust port thereinto.

From the above it is evident that assuming the combination being so designed that a relatively small plug 9 is sufficient for ordinary circumstances to produce the ideal relation of draft on the furnace of the boiler and the engine for example is to be used where steeper grades and harder Work is required of same, necessitates greater draft on the furnace, a larger plug 9 may be installed to thus increase such draft without producing abnormal back-pressure, and thus effect the efiiciency of the engine.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

In a locomotive boiler having engine exhaust ports leading into the smoke box thereof, an upright cylindrical nozzle within said smoke box surrounding the termini of said ports, a central division wall within said nozzle forming a single passageway over each port, and an unobstructed expansion chamber, common to both of said passageways, within said nozzle above the upper end of said division wall and the full diameter of the interior of said nozzle, and means for selective control of the discharge from said expansion chamber, said exhaust ports, passageways and space about said selective control means being substantially constant in cross sectional area throughout to avoid any back-pressure on the cylinders of said locomotive, and resulting in an unobstructed exhaust discharge from said expansion chamber during the alternate functioning of said passageways.

ABRAM M. BEVIER. 

